The present disclosure is related to a variable magnification optical system and an imaging apparatus. More particularly, the present disclosure is related to a variable magnification optical system which is favorably suited for use in long distance surveillance cameras, and to an imaging apparatus equipped with the variable magnification optical system.
Conventionally, surveillance cameras are employed to prevent crime, to record scenes, etc., and the number thereof is increasing recently. Variable magnification optical systems are preferably utilized as lens systems for surveillance cameras in scenes that require high general use properties. Among such variable magnification optical systems, there is a trend for configurations in which the lens group provided most toward the object side does not move when changing magnification to be preferred. Known variable magnification optical systems in which the lens group provided most toward the object side are fixed when changing magnification are disclosed in Japanese Unexamined Patent Publication Nos. H9(1997)-325269 and H4(1992)-191811, for example.